Cephennium gallicum Ganglbauer, 1899
This is a mostly central and northern European species most frequently recorded from northern Spain to Switzerland and Germany and north to the UK and southern Fennoscandia, it has also recently been recorded from North America and seems to have become established, making it the first Palaearctic member of the family to do so. It is widespread but very local across England and Wales though absent from much of the West Country and very scarce in the north, it has not been found on the islands but its small size and secluded habits would suggest that it is under-recorded. Little is known of the biology but in Europe adults generally occur in deciduous woodland with plenty of decaying wood while in the United States they occur under bark on damaged or recently fallen pine trees. Adults are active over a long season from April until late in the autumn, they have been recorded among debris under the bark of a range of broadleaf trees including poplar (Populus L.), willow (Salix L.), oak (Quercus L.) and beech (Fagus sylvatica L.), and they usually occur under loose bark on trees that have been dead for several seasons and where the phloem has been extensively destroyed by bark beetles. Beyond this they may be swept from low vegetation in wooded areas and have often been recorded from moss and accumulated litter and wood debris at the base of dead trees. Adults are active at night when have been observed feeding on oribatid mites, which is a general feeding strategy for members of the family. They are tiny but readily seen on the surface of bark by torchlight and removing loose bark will sometimes reveal them but taking samples of debris for extraction is probably the best way to record the species.
1.1-1.3 mm. Elongate and discontinuous in outline, entirely black or dark brown, often with the forebody paler than the elytra, with fine and slightly-raised pubescence throughout , appendages brown. Head transverse and widest across convex and protruding eyes, temples short and sub-parallel although usually retracted into the thorax and so not visible, vertex weakly convex and smooth behind a distinct arcuate fronto-clypeal suture, labrum truncate anteriorly, maxillary palps distinctive; four segmented, second segment long and thin, third segment expanded and curved internally and the terminal segment broad and very short. Antennae inserted laterally in front of the eyes, 11-segmented with a long and narrow three-segmented club. Pronotum transverse, broadest about the middle and narrowed to near-perpendicular posterior angles and curved (from above) anterior margin, surface finely and rather sparsely punctured and evenly convex or slightly uneven towards the base, without basal fovea or furrows, basal margin straight medially and recurved towards the angles. Scutellum transverse and triangular with several very fine but distinct transverse ridges. Elytra elongate and broadest near the middle, about as wide as the pronotum, with slightly protruding shoulders and evenly curved laterally to a continuously-curved apical margin that leaves the abdominal apex exposed, surface without striae, randomly and rather sparsely punctured throughout and with pale, slightly raised pubescence. Legs long and slender with femora broadly visible in normal setting, tibiae smooth and only weakly broadened from the base, tarsi with five normal segments, claws paired, and smooth and not toothed at the base. Readily identified among our species by the form of the antennae and palps, the smooth pronotum and the overall shape.
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